function drawVisualization() {
  // Create and populate the data table.
  var data = google.visualization.arrayToDataTable([
    ['Location', 'Parent', 'Market trade volume (size)', 'Market increase/decrease (color)'],
    ['Global',    null,                 0,                               0],
    ['America',   'Global',             0,                               0],
    ['Europe',    'Global',             0,                               0],
    ['Asia',      'Global',             0,                               0],
    ['Australia', 'Global',             0,                               0],
    ['Africa',    'Global',             0,                               0],
    ['Brazil',    'America',            11,                              10],
    ['USA',       'America',            52,                              31],
    ['Mexico',    'America',            24,                              12],
    ['Canada',    'America',            16,                              -23],
    ['France',    'Europe',             42,                              -11],
    ['Germany',   'Europe',             31,                              -2],
    ['Sweden',    'Europe',             22,                              -13],
    ['Italy',     'Europe',             17,                              4],
    ['UK',        'Europe',             21,                              -5],
    ['China',     'Asia',               36,                              4],
    ['Japan',     'Asia',               20,                              -12],
    ['India',     'Asia',               40,                              63],
    ['Laos',      'Asia',               4,                               34],
    ['Mongolia',  'Asia',               1,                               -5],
    ['Israel',    'Asia',               12,                              24],
    ['Iran',      'Asia',               18,                              13],
    ['Pakistan',  'Asia',               11,                              -52],
    ['Egypt',     'Africa',             21,                              0],
    ['S. Africa', 'Africa',             30,                              43],
    ['Sudan',     'Africa',             12,                              2],
    ['Congo',     'Africa',             10,                              12],
    ['Zair',      'Africa',             8,                               10]
  ]);

  // Create and draw the visualization.
  var treemap = new google.visualization.TreeMap(document.getElementById('visualization'));
  treemap.draw(data, {
    minColor: 'red',
    midColor: '#ddd',
    maxColor: '#0d0',
    headerHeight: 15,
    fontColor: 'black',
    showScale: true});
}
